1. Bioactive Compounds Laboratory; Food Science and Technology Institute, Federal University of Rio Grande do Sul; Avenue Bento Gonçalves Number 9500, P. O. Box 15059 Porto Alegre Rio Grande do Sul 91501-970 Brazil
2. Chemistry Institute, Federal University of Rio Grande do Sul; Avenue Bento Gonçalves Number 9500, P. O. Box 15003, Porto Alegre Rio Grande do Sul 91501-970 Brazil
3. Faculté des Sciences de l'Agriculture et de l'Alimentation; Pavillon Paul Comtois, Université Laval; Québec G1V 0A6 Canada
4. Food Science and Nutrition Department; National Research Center; Egypt